Chocolate chip cookie FLOPS! Please Help

Could you possibly be using baking soda by accident instead of baking powder (assuming that's what the recipe calls for)? If you're sure you're using baking powder, check its expiration date.

I'm sure there are many variables as to why her recipie didn't work for you. Oven temps vary, ingredients vary (quality, brand, substitutions ect), mixing by hand vs a handmixer vs a kitchenaid mixer ect. But I've used this recipie several times and my FAMILY LOVES IT! http://allrecipes.com/Recipe/Soft-Chocolate-Chip-Cookies-II/Detail.aspx it says not to double the batch I have and didn't have any problems with them turning out. My hubby who doesn't care for sweets usually has a handful of them so they have to be good. And as always read the tips & comments by people. I think a double batch maybe lasts 3 days tops in my house

If the recipe works for your aunt, it should work for you. There might be other things going on to make them not turn out right. I'm assuming your following the directions exactly so let's look at other possibilities. Your oven may not be calibrated right and your thermostat is off. You may have to either have it fixed or adjust the minutes you bake your cookies. It could be the pans you are using. I use the insulated cookie sheets and it does make a difference. You need to make the cookies with your aunt to see how she does it. Sometimes just following the recipe isn't enough.